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Biomedical subjects

H M Emrich

Publications and source records attributed to H M Emrich.

At least 37 records · Page 2Linked to original sources
PubMed2001

Discrepant target detection and action monitoring in obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) has been related to altered mechanisms of action monitoring and target detection, and it has been hypothesized that hyperactive striatal-cortical circuits constitute the underlying pathophysiology. This study used event-related brain potentials (ERPs) to explore this hypothesis. A choice reaction time experiment was carried out in a group of OCD patients and a normal comparison group. The P3b component of the ERP to targets was taken as an indicator of the target-evaluation process and the response-locked error-related negativity (ERN) served as an indicator of action monitoring. We hypothesized that the OCD group would show a shortened P3b latency and an amplitude-enhanced ERN. Consistent with our expectations, the P3b latency was shorter and the ERN amplitude was higher in the OCD group. Unexpectedly, we also observed a prolonged ERN latency in the OCD group and a more posterior topography of this component. The data provide partial support for the hypothesis of a hyperactive neural network in OCD. In addition the disorder must involve pathophysiological processes that are presumably related to other aspects of its complex and heterogeneous clinical hallmarks.

Adult↗
PubMed2001

Estradiol levels in psychotic disorders.

Estradiol has been postulated to constitute a protective factor for schizophrenia, which could provide women at risk to experience a psychotic episode with a relative protection in phases of high estradiol levels, i.e. before menopause and during the peri- and postovulatory phases of their cycle. Women suffering from schizophrenia have been reported to show significantly lower estradiol levels than the normal population and to experience first onset or recurrence of a psychotic episode significantly more often in low estrogen phases of the cycle with low estradiol levels. We examined estradiol levels in an open prospective study in 43 women admitted with a diagnosis of an acute psychotic episode and could confirm these findings for schizophrenia as well as other psychotic disorders. Only 28% of the women exhibited estradiol and progesterone levels indicating a peri- or postovulatory phase and all of the estradiol levels on admission were either within the lower part of the cycle-dependent normal range or below normal; comparison with a control group of healthy volunteers and patients admitted with different psychiatric diagnoses confirmed their estradiol levels to be significantly higher. However, when splitting this control group, the statistical difference would only hold between the study group of psychotic patients and the healthy control group. The group of patients with other diagnoses than a psychotic episode fell in between of the other two groups and did not differ significantly from either. Thus, an unspecific effect, i.e. a hypothalamic downregulation due to the stress of acute hospitalization must be born in mind when assessing hormone levels in acutely psychotic women.

Adult↗
PubMed2001

Altered inhibition of motor responses in Tourette Syndrome and Obsessive-Compulsive Disorder.

OBJECTIVES: The Gilles de la Tourette Syndrome (TS) and Obsessive Compulsive Disorder (OCD) have been shown to display impaired cognitive and motor inhibition. This study investigated inhibitory mechanisms of motor responses in order to expand the understanding of sensorimotor integration processes in both disorders. We hypothesized that both patient groups would display altered frontal inhibitory activity. MATERIAL AND METHODS: To this end event-related brain potentials (ERPs) were recorded in a STOP-paradigm in groups of TS and OCD patients and in a control group. The paradigm required the execution of a motor response after a "go" signal was given and the occasional suppression of this response after a second "stop" signal occurred. RESULTS: Behavioral parameters and Lateralized Readiness Potential (LRP) confirmed that both patient groups were well able to initiate motor responses. "Go" and "stop" stimuli elicited an enhanced frontal negative activity in both patient groups. In addition, "stop" stimuli were associated with a frontal shift of the NoGo-Anteriorization (NGA) in the TS group but not in the OCD group. CONCLUSIONS: The data are interpreted to indicate altered frontal inhibitory functions. Similarities and dissimilarities between the findings for TS and OCD are discussed with respect to other pathophysiologic aspects of the disorders.

Adolescent↗
PubMed2001

[Addiction as a life style: on the social anthropology of addiction].

Regularly the unsolved problems of addiction- and dependence-research are discussed in the sense of the psycho-body-dichotomy, arguing that the biological mechanisms of reward-systems and their pathobiochemistry have to be confronted with the psychological and philosophical/anthropological dimensions within persons. The present paper, however, tries to demonstrate that this dichotomy is insufficient insofar as social-anthropological components of being addicted, which represent integrative constituents of a theory of addiction, are neglected within such a scheme. The developmental-psychological and philosophical-psychological aspects of socialization are considered and related to internal valuating systems and reality models regarding the problems of drugs and dependency. Herein it is shown that especially the model of René Girard, constituting "mimetic triangulation", is applicable to the understanding of the microsocialization of drug-consumers. This is also demonstrated in film-examples. It is shown that the problem of drug-addiction cannot be solved from a neurobiological/biochemical--and also a psychotherapeutic/psychoanalytic concept--without incorporating the dynamics and the value-worlds within groups which should also be considered to be therapeutically influenceable.

Anthropology, Cultural↗
PubMed2001

[Clomethiazole as an adjuvant in the treatment of confusional psychosis].

We report on the successful treatment of two female patients with the clinical features of severe confusional psychosis. The clinical picture of these cases was characterized by lability of mood, disorientation, delusions, hallucinations, misidentification of persons, severe thought disorder and impaired memory. A 55-year old female inpatient suffered from a psychotic episode with the clinical features of confusional psychosis. Medical history showed three proceeding confusional psychotic episodes. In the second case a 32-year old female inpatient suffered from a severe postpartum psychosis with the clinical features of confusional psychosis. In this case there was no clinical history of psychotic episodes. After nonresponsive treatment with neuroleptics and mood-stabilizers, both responded rapidly to additional medication with clomethiazole within a week, exhibiting a marked reduction in clinical signs and symptoms. A brief review about this delirium-like psychosis and current knowledge of therapeutic strategies is presented. We discuss clomethiazole as a possible potential adjunct in the treatment of confusional psychoses.

Adult↗
PubMed2001

Influence of treatment of Tourette syndrome with delta9-tetrahydrocannabinol (delta9-THC) on neuropsychological performance.

Previous studies have suggested that marijuana (cannabis sativa) and delta-9-tetrahydrocannabinol (delta9-THC), the major psychoactive ingredient of marijuana, are effective in the therapy of tics and associated behavioral disorders in Tourette Syndrome (TS). Because there is also evidence that cannabis sativa may cause cognitive impairment in healthy users, we performed a randomized double-blind placebo-controlled crossover trial for delta9-THC in 12 adult TS patients to investigate whether treatment of TS with a single dose of delta9-THC at 5.0 to 10.0 mg causes significant side effects on neuropsychological performance. Using a variety of neuropsychological tests, we found no significant differences after treatment with delta9-THC compared to placebo treatment in verbal and visual memory, reaction time, intelligence, sustained attention, divided attention, vigilance, or mood. Only when using the Symptom Checklist 90-R (SCL-90-R) did our data provide evidence for a deterioration of obsessive-compulsive behavior (OCB) and a trend towards an increase in phobic anxiety. However, these results should be interpreted with caution as SCL-90-R has known limitations on measuring OCB. We suggest that the increase in phobic anxiety is mainly due to the fact that a single-dose treatment rules out the possibility of administering the dosage slowly. In contrast to results obtained from healthy marijuana users, a single-dose treatment with delta9-THC in patients suffering from TS does not cause cognitive impairment. We therefore suggest that further investigations should concentrate on the effects of a longer-term therapy of TS with delta9-THC.

Adolescent↗
PubMed2001

Oxcarbazepine in affective and schizoaffective disorders.

Anticonvulsants have been successfully used in pharmacopsychiatry after their therapeutic value in affective and schizoaffective disorders had been documented in several clinical trials. As the authorities in several countries registered newer anticonvulsants with fewer side effects, their therapeutic value in psychiatric disorders was studied. Clinical studies from the early 80's onward have demonstrated the efficacy of oxcarbazepine (OCBZ), a keto derivative of carbamazepine, in treating mania in affective and schizoaffective disorders. In addition, OCBZ has a distinct pharmacokinetic profile concerning drug-drug interactions compared to carbamazepine and other anticonvulsants. Therefore, the value of OCBZ in the treatment of affective and schizoaffective disorders needs to be evaluated. We reviewed the literature with regard to pharmacokinetic and pharmacodynamic characteristics of OCBZ, drug-drug interactions relevant in pharmacopsychiatry, and the clinical effects of OCBZ in the treatment of patients with affective and schizoaffective disorders. According to the literature, OCBZ is regarded as effective in acute mania and appears to reduce the dosage of neuroleptics required for the treatment of affective and schizoaffective disorders. In addition, it has a preferable pharmacokinetic profile with less severe side effects compared to carbamazepine and neuroleptics. Furthermore, since OCBZ does not interact substantially with the cytochrome P450 enzyme system, co-administration with neuroleptics or antidepressants appears to be well tolerated in affective disorders. However, despite promising effects of OCBZ, few clinical studies have been published in the last 15 years. We conclude that further studies should validate the efficacy of OCBZ in treating mania and evaluate possible pharmacopsychiatric indications as well as limitations for this psychotropic compound.

Anticonvulsants↗
PubMed2001

Prevalence of dissociative disorders among psychiatric inpatients in a German university clinic.

The aim of the study was to determine the frequency of dissociative disorders among psychiatric inpatients in Germany and to investigate the relationship between childhood trauma and dissociation. The German version of the Dissociative Experiences Scale (DES), the Fragebogen für Dissoziative Symptome (FDS), was used to screen 115 consecutive inpatients admitted to the psychiatric clinic of a university hospital. Patients with FDS scores higher than 20 were interviewed by a trained clinician, using the German translation of the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D-R). The German version of the Childhood Trauma Questionnaire (CTQ) was administered to investigate prevalence of childhood trauma and relations between childhood trauma and dissociation in adult life. Twenty-five of the 115 patients (21.7%) had a score higher than 20 on the FDS. Of these, 15 patients were interviewed with the SCID-D-R. One patient was diagnosed with a dissociative identity disorder, three with dissociative disorders not otherwise specified, and one patient with depersonalization disorder. All diagnoses were confirmed clinically. A significant positive relationship was found between the severity of childhood trauma and dissociation. Dissociative disorders are common among German psychiatric inpatients. Clinicians who work in psychiatric inpatient units should be mindful of these disorders.

Adolescent↗
PubMed2001

Differential effects of emotional content on event-related potentials in word recognition memory.

The aim of this study was to delineate the influence of the emotional content of stimuli to be remembered on the recognition performance of normal subjects by means of the event-related potential (ERP) technique. When words are presented repeatedly, brain responses to repeated and recognized items are characterized by a more positive waveform, referred to as "old/new effect". Words judged for their emotional connotation ("negative", "positive" and "neutral") were presented successively on a video monitor to subjects, who had the task to indicate whether a given word occurred for the first ("new") or second ("old") time within the list by pressing one of two buttons. For each word category, the ERPs of the old words were more positive compared to those of the new items from about 250 ms after stimulus. The old/new effect was significantly enhanced for the negative and positive items compared to the neutral stimuli between 450 and 650 ms after stimulus pointing to a significant influence of the emotional content of words on verbal memory processes. This paradigm appears to be feasible to investigate interactions of emotion and cognition in psychiatric patients.

Adult↗
PubMed2000

High frequency repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex in schizophrenic patients.

Repetitive transcranial magnetic stimulation (rTMS) has been tried therapeutically in major depression. In order to investigate the therapeutic efficacy of rTMS in psychotic patients, 12 participants (four women, eight men) with schizophrenia according to DSM-IV criteria, aged 25 to 63 years (mean (+/-s.d) 40.4+/-11.0), were enrolled in the study. Following a double-blind crossover design, patients were treated at random with 2 weeks of daily left prefrontal rTMS (20 2s 20 Hz stimulations at 80% motor threshold over 20 min, dorsolateral preforntal cortex) and 2 weeks of sham stimulation. The Brief Psychiatric Rating Scale decreased under active rTMS (p <0.05), whereas depressive symptoms (BDI) and anxiety (STAI) did not change significantly. Prefrontal rTMS might be effective in the non-pharmacological treatment of psychotic patients.

Adult↗
PubMed2000

Emotion/cognition-coupling in word recognition memory of depressive patients: an event-related potential study.

Depressive patients show deficits in memory functions. However, the underlying mechanisms remain unclear. Experiments with a special emphasis on the link between emotion and cognition appear challenging. The aim of this study is to investigate the influence of the emotional content of words on memory in non-medicated depressive patients (n=11) compared with a control group (n=11) utilizing event-related brain potentials (ERPs). In a continuous word recognition paradigm brain responses to repeated items are characterized by more positive waveforms of ERPs. This recognition effect ('old/new effect') has been shown to be sensitive to parameters relevant for memory processing. For the purpose of this ERP experiment visually presented words were classified into three different categories of emotional content. The ERPs for the correctly detected 'old' (repeated) words showed an increased positivity beginning approximately 250 ms post-stimulus, concurring with a good recognition performance. In addition, old/new effect and behavioral data were sensitive to words' different emotional connotations in the control group. In contrast, the depressive patients performed worse and showed no significant old/new effect. Nevertheless, their recognition performance was also enhanced by the emotional content. Furthermore, a differential effect of the emotional content on frontal ERPs was found between groups. In contrast to the control group, a reduced old/new effect indicates a reduced working memory capacity in the moderately depressed patients. This is suggested to be partially due to changes of the emotion/cognition coupling related to ruminations with preferably negative emotional connotation. However, the emotional content also affects recognition performance in the depressive patients.

Adult↗